add findByParent method to ComColDataService

src/app/core/data/collection-data.service.ts

@@ -1,6 +1,6 @@
 import { Injectable } from '@angular/core';
 
-import { distinctUntilChanged, filter, map, take } from 'rxjs/operators';
+import { distinctUntilChanged, filter, map, switchMap, take } from 'rxjs/operators';
 import { Store } from '@ngrx/store';
 
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
@@ -136,4 +136,10 @@ export class CollectionDataService extends ComColDataService<Collection> {
     return this.rdbService.buildList(href$);
   }
 
+  protected getFindByParentHref(parentUUID: string): Observable<string> {
+    return this.halService.getEndpoint('communities').pipe(
+      switchMap((communityEndpointHref: string) =>
+        this.halService.getEndpoint('collections', `${communityEndpointHref}/${parentUUID}`)),
+    );
+  }
 }

src/app/core/data/comcol-data.service.ts

@@ -1,6 +1,15 @@
-import { distinctUntilChanged, filter, map, mergeMap, share, take, tap } from 'rxjs/operators';
+import {
+  distinctUntilChanged,
+  filter, first,
+  map,
+  mergeMap,
+  share,
+  switchMap,
+  take,
+  tap
+} from 'rxjs/operators';
 import { merge as observableMerge, Observable, throwError as observableThrowError } from 'rxjs';
-import { isEmpty, isNotEmpty } from '../../shared/empty.util';
+import { hasValue, isEmpty, isNotEmpty } from '../../shared/empty.util';
 import { NormalizedCommunity } from '../cache/models/normalized-community.model';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { CommunityDataService } from './community-data.service';
@@ -60,7 +69,11 @@ export abstract class ComColDataService<T extends CacheableObject> extends DataS
     }
   }
 
-  public findByParentCommunity(parentUUID: string): Observable<RemoteData<PaginatedList<T>>> {
-    this.halService.getEndpoint(`communities/${parentUUID}/collections`)
+  protected abstract getFindByParentHref(parentUUID: string): Observable<string>;
+
+  public findByParent(parentUUID: string, options: FindListOptions = {}): Observable<RemoteData<PaginatedList<T>>> {
+    const href$ = this.buildHrefFromFindOptions(this.getFindByParentHref(parentUUID), [], options);
+    return this.findList(href$, options);
   }
+
 }

src/app/core/data/community-data.service.ts

@@ -1,4 +1,4 @@
-import { filter, take } from 'rxjs/operators';
+import { filter, switchMap, take } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 
 import { Store } from '@ngrx/store';
@@ -9,7 +9,7 @@ import { Community } from '../shared/community.model';
 import { ComColDataService } from './comcol-data.service';
 import { RequestService } from './request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { FindListOptions, FindAllRequest } from './request.models';
+import { FindListOptions, FindListRequest } from './request.models';
 import { RemoteData } from './remote-data';
 import { hasValue } from '../../shared/empty.util';
 import { Observable } from 'rxjs';
@@ -50,7 +50,7 @@ export class CommunityDataService extends ComColDataService<Community> {
       filter((href: string) => hasValue(href)),
       take(1))
       .subscribe((href: string) => {
-        const request = new FindAllRequest(this.requestService.generateRequestId(), href, options);
+        const request = new FindListRequest(this.requestService.generateRequestId(), href, options);
         this.requestService.configure(request);
       });
 
@@ -64,10 +64,18 @@ export class CommunityDataService extends ComColDataService<Community> {
         filter((href: string) => hasValue(href)),
         take(1))
         .subscribe((href: string) => {
-          const request = new FindAllRequest(this.requestService.generateRequestId(), href, options);
+          const request = new FindListRequest(this.requestService.generateRequestId(), href, options);
           this.requestService.configure(request);
         });
 
     return this.rdbService.buildList<Community>(hrefObs) as Observable<RemoteData<PaginatedList<Community>>>;
   }
+
+  protected getFindByParentHref(parentUUID: string): Observable<string> {
+    return this.halService.getEndpoint(this.linkPath).pipe(
+      switchMap((communityEndpointHref: string) =>
+        this.halService.getEndpoint('subcommunities', `${communityEndpointHref}/${parentUUID}`))
+    );
+  }
+
 }

src/app/core/data/data.service.ts

@@ -15,7 +15,7 @@ import {
   CreateRequest,
   DeleteByIDRequest,
   FindListOptions,
-  FindAllRequest,
+  FindListRequest,
   FindByIDRequest,
   GetRequest
 } from './request.models';
@@ -133,7 +133,7 @@ export abstract class DataService<T extends CacheableObject> {
     hrefObs.pipe(
       first((href: string) => hasValue(href)))
       .subscribe((href: string) => {
-        const request = new FindAllRequest(this.requestService.generateRequestId(), href, options);
+        const request = new FindListRequest(this.requestService.generateRequestId(), href, options);
         if (hasValue(this.responseMsToLive)) {
           request.responseMsToLive = this.responseMsToLive;
         }
@@ -191,7 +191,7 @@ export abstract class DataService<T extends CacheableObject> {
   }
 
   /**
-   * Make a new FindAllRequest with given search method
+   * Make a new FindListRequest with given search method
    *
    * @param searchMethod The search method for the object
    * @param options The [[FindListOptions]] object
@@ -205,7 +205,7 @@ export abstract class DataService<T extends CacheableObject> {
     hrefObs.pipe(
       first((href: string) => hasValue(href)))
       .subscribe((href: string) => {
-        const request = new FindAllRequest(this.requestService.generateRequestId(), href, options);
+        const request = new FindListRequest(this.requestService.generateRequestId(), href, options);
         request.responseMsToLive = 10 * 1000;
         this.requestService.configure(request);
       });

src/app/core/data/request.models.ts

@@ -147,7 +147,7 @@ export class FindListOptions {
   startsWith?: string;
 }
 
-export class FindAllRequest extends GetRequest {
+export class FindListRequest extends GetRequest {
   constructor(
     uuid: string,
     href: string,